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MAC to IP resolution between Wireless Controller and NAC

MAC to IP resolution between Wireless Controller and NAC

New Contributor II
We are having trouble with guests completing the captive portal registration on the NAC. This is apparently a MAC-to-IP resolution issue between the EWC and the NAC. The subnet for the captive portal is 10.200.x.x and the DHCP is handled by the EWC's onboard DHCP for the topology.

I doing something wrong because the NAC is not resolving these addresses therfor they connot complete registration. The information from the switches resolves perfectly but not from this "guest" subnet. I am sure there is a check box somewhere I am missing, any help?


As you mentioned that NAC portal is not in same subnet, I think the ip-helper or bootp relay configuration would be need in core switch so that the NAC could get the DHCP packets for MAC-to-IP resolution.

SNMPv3 is configured and working. I will check the logs

The EWC should be sending it over, but an additional ip-helper wouldn't hurt.
Please verify SNMPv3.
you can further check the logs on NAC to identify why IP-to-MAC resolution is failing.


The local DHCP server in the EWC is providing IP Adresses. Would the ip-helper still be useful? I assume the NAC would be "sniffing" dhcp traffic.

New Contributor II
"If I unterstand that correctly you can't ping the guest client from the NAC - correct ?"
Not sure what I said that led you to think this. I can ping clients from the NAC.

"Do you use the main interface on the NAC for the guest auth"

Yes. We use the main interface. Would using a secondary interface improve performance?